I wonder is there likely to be any feasible way of advancing the spark position of an AC powered CDI ignition system, so it provides max total advance of something like 30 degrees at 3000rpm?
The system I am thinking of has an internal rotor, and a trigger coil incorporated into the stator, which works from the magnets in the rotor itself. From tests I have done with these systems, it seems as though they quickly advance 17-18 degrees at around 1000rpm.
Problem is that for best possible running a 4T motor needs to have max ignition advance at the position where max torque is generated, which for this application is around 3000rpm. These AC systems also seem to suffer from timing scatter as engine speeds increase, and I have found running is sometimes improved by re-fitting points triggered inductive systems!
Only thing I have seen to help with this is a very crude box which delays the point where the start retard feature is switched off................however while in some cases these improve low speed operation, they seem to drastically effect higher speed running.
Its pretty much impossible to find any accurate info on the above, and there seems to an enormous amount of confusion over these AC CDI ignitions, even to the extent that some people believe crude analog systems are "digital" and can be programmed in some way!
The system I am thinking of has an internal rotor, and a trigger coil incorporated into the stator, which works from the magnets in the rotor itself. From tests I have done with these systems, it seems as though they quickly advance 17-18 degrees at around 1000rpm.
Problem is that for best possible running a 4T motor needs to have max ignition advance at the position where max torque is generated, which for this application is around 3000rpm. These AC systems also seem to suffer from timing scatter as engine speeds increase, and I have found running is sometimes improved by re-fitting points triggered inductive systems!
Only thing I have seen to help with this is a very crude box which delays the point where the start retard feature is switched off................however while in some cases these improve low speed operation, they seem to drastically effect higher speed running.
Its pretty much impossible to find any accurate info on the above, and there seems to an enormous amount of confusion over these AC CDI ignitions, even to the extent that some people believe crude analog systems are "digital" and can be programmed in some way!